For comics readers, the details of Civil War and its aftermath are well known, but for the uninitiated, here is what you need to know about the storyline and the way it could be brought to the big screen:

1. Marvel's mightiest event

While not the first of its kind, the 2006-07 line-wide crossover with its core series and tie-in miniseries and one-shots set the standard for the way such stories would be handled by Marvel (and DC) Comics for years to come.

Mark Millar and Steve McNiven's seven-issue Civil War series still dominates the list of bestselling comics of the 21st century. It launched a pattern of yearly events which continued with Secret War, Siege, Fear Itself, Avengers vs X-Men and many more.

2. Hero vs hero

Marvel Comics

Although a few villains make an appearance in the story, this isn't about them. As the name implies, Civil War is a battle that wages between Marvel's superheroes. On one side are the supporters of the new Superhero Registration Act, led by Tony Stark, with Captain America heading a group who oppose government co-option and the forced unmasking of heroes and vigilantes.

The Avengers and Fantastic Four were at the heart of the conflict, although the X-Men and solo heroes including Daredevil, Doctor Strange and Spider-Man also had a part to play in the unfolding conflict.

3. The worst side of Tony Stark

Iron Man comes off particularly poorly in the story. Painted as a totalitarian, his methods were deemed to be out of character by some fans. He declares war on his oldest friend, imprisons his former allies in an interdimensional prison and commits some serious acts of violence.

If the films stick closely to the Civil War comic, Downey Jr's character will be coming out the other side looking decidedly tarnished.

4. Spider-Man's unmasking

One particularly memorable part of the event was the voluntary, public unmasking of Spider-Man (as with many things in comics, it did not stick). After what was (from readers' point-of-view, at least) 50 years of Peter Parker's carefully kept secret identity being revealed, this was big news.

Of course, Spider-Man doesn't feature in Marvel Studios' films (not yet), but the unmasking could be duplicated with any other masked hero in the cinematic continuity.

5. Things get dark

Civil War was punctuated by a series of grim and gritty moments - the splitting of the Fantastic Four, the unleashing of a murderous Thor clone and the pulverising of Spider-Man at the hands of Iron Man to name but a few.

Marvel's films have been marked with a sense of humour that might not easily translate into this storyline. Dark times could well be ahead for the Avengers.

6. Cap doesn't make it

While not part of the main miniseries, Civil War had one particularly memorable result. After surrendering to the pro-registration forces, Steve Rogers is gunned down outside of a courthouse during his trial, leading to a period in which Bucky Barnes/the Winter Soldier takes up the mantle of Captain America.

There have been rumours that Cap's death may be on the cards in the movies. And we already have a Winter Soldier waiting in the wings. We're just saying...

Captain America 3 is scheduled for release on April 29, 2016 in the UK and May 6, 2016 in the US. A subtitle for the film is yet to be announced.

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